Apparatus for heating motor vehicle door keys



A. J. DRUGAN 2,530,513

APPARATUS FOR HEATING MOTOR VEHICLE noon KEYS Nov. 21, 1950 Filed April 7, 1949 W A A -w w ug M Aiiorneq Patented Nov. 21, 1950 UNITED STATES rareur OEFIE APPARATUS FOR HEATING MOTOR VEHICLE DOOR KEYS Allan J. Drugan, Columbus, Ohio Application April 7, 1949, Serial No. 86,075

2 Claims. 1

This invention relates to electrical heating apparatus and, more particularly, :to appliances in which heat is generated by the passage of electric current through one or more resisting conductors.

In one of its more specific aspects, the present invention has for an object thereof to provide a simple, reliable and positive acting means for heating the actuating keys of door locks and, through the insertion of such heated keys, the .door locks themselves, whereby to provide means for efiecting free and easy actuation of such locks during periods of cold weather when, .as a result of the freezing-of moisture accumulations in the lock barrels, the actuation of the locks is likely to be rendered most difficult, if not impossible, to perform.

The freezing of key-actuated door locks is apt to be encountered in any lock exposed to outdoor weather conditions. It is commonly encountered in motor vehicle door locks after a motor vehicle has been left standing during cold weather in exposed locations. Therefore, it is another object of the present invention to provide an electrically energized key heater adapted for installation on motor vehicles and .so arranged as to provide a means accessible from the exterior .of a vehicle :to heat the operating door key thereof, so that the key in a heated state may be inserted in the door lock and, through heat exchange with the latter, .to elevate the temperature of the lock to *a point admittin of its ready actuation by customary key insertion and manipulation.

It is another object of the invention to provide a key heater having a casing formed with an entrance :for the shank of a key, .and wherein the interior of the casing is provided with electrically energized resistance elements, the latter being so disposed that when energized, heat emanating therefrom is directed upon the shank of a (key inserted in the casing, whereby to effeet a quick heating 101? the key to door lock releasing temperatures.

A further object is to provide a device of the character set forth 'lll'WhiCh currentflow through the resistor elements of the :deviceiis effected automatically when a key is inserted in the heater and, conversely, discontinued automatically when a heated key is withdrawn from the de-' V108.

For a further understanding of the invention, reference is to be had to the -f01lOW-i1'lg description and the accompanying drawing, wherein:

Fig. 1 is a fragmentary top plan View of a,

motor vehicle illustrating diagrammatically the position of the key-heating device comprisin the present invention on the vehicles;

Fig. 2 is a vertical longitudinal sectional view taken through my improved key-heating device;

Fig. 3 is a horizontal sectional view taken through the device on the plane disclosed 'by the of Fig. 2;

4 is a front elevational View of the device;

Fig. 5 is a vertical transverse sectional view taken on the plane disclosed by the line 5--5 of Fig. "2;

Fig. 6 is a detail vertical sectional view disclosin the key-energized actuating switch for controlling the how of current through the heat ing resistors of my improved device.

Referring more particularly to the drawing, the numeral ii] designates the cylindrical sheet metal casing of the key-heating device comprising the present invention. At its inner end, the casing is formed with an out-turned flange I for enagem' nt with the outer peripheral portion of a facing disk 12 in which is formed a key shankreceiving slot 13. The flange l! and the peripheral portion of the disk !2 are united by means of the headed screws, indicated at M. One of the screws, as shown in Fig. 2, is joined with a terminal 25 of a conductor l5, which extends to a source of electrical energy such as the conventional storage battery I l of a motor vehicle l8.

At its outer end, the casing I0 is provided with an inturned flange !9, which constitutes a seat for an outer disk 20 formed from an electrical insulating material. The disk is formed with an axial opening 22 in which is positioned a metallic stud 22, the latter being formed With a circular fin 23 having seating engagement on the inner surface of the disk 25] around the opening 25 therein. The stud projects through the opening 2'! and beyond the outer face of the disk 29, such exteriorly projecting portion being externally threaded for the reception of a pair of binding nuts 24. The inner of these nuts serves to clamp the stud in seated engagement with the disk 25, while the outermost of the nuts 24 acts as a clamping means in securing an apertured terminal clip 25 of an electrical conductor 26 to the stud. The conductor 25 leads to a terminal of the storage battery I! opposed to that with wh ch the conductor i 6 is joined.

The portion of the stud disposed longitudinally and axially within the casing Ii) is provided with external longitudinally extending scoring 21 and with an annular groove 28. Positioned on the scored portion 27 of the stud is a pair of separable dielectric resistor carriers 29. These carriers are provided with adjoining faces which are longitudinally grooved as at 38 to receive the stud 22, as shown more particularly in Fig. 5. Also, the adjoining faces of said carriers may be formed with longitudinally extending grooves 3! for the reception of ribs 32 provided in an opposite or complemental carrier. To hold the carriers together as a unit, I employ advantageously a pair of longitudinally spaced U-shaped brackets 33 which are recessed as at 34 into the carriers. The brackets may be provided with threaded openings for the reception of the shanks of screws 35, the threaded ends of which are accessible from the exterior of the casing l0 and occupy tapered or countersunk seats 36 in the casing walls.

The stud is provided with an axial passage 31 in which are secured a pair of wires 38, constituting heating resistors. The e wires are secured at one end as at 39 against movement to the outer end of the stud 22, the wires passing inwardly lengthwise of the passageway 31 and diverging from the inner end of said passageway in order to permit said wires to be trained around heater support pins as projectin laterally from the sides of the resistor carrier blocks 29. Intermediatel of their length, the blocks are formed to provide an opening 4! in registration with the shank of a key inserted in the heater, so that the heat developed by the energizing of the wires 38 may be transmitted readily to the key shank. At the end of the lock opposite to that carrying the stud 22, the carrier blocks have their adjoining faces provided with a slot 42 which registers with the slot I3 of the disk I2 for the passage of the key shank, the latter being indicated at E3 in dotted lines in Figs. 2 and 3.

To control current flow through the wires and the energizing of the heater, the wires 38, after passing around the pins 40, are trained through grooves 44 formed in the outer surfaces of the blocks 29. As indicated more particularly in Fig. 6, the wires 38, where they pass around the front end of the carrier block 29, are arranged adjacent to but normally in spaced relation from a resilient switch arm 45. This arm has one of its ends clamped between the disk l2 and the flange ii, so that the inner end of the arm, which is oiiset as at 46, will be disposed in registration with the slot !3, so that it will be in the path of movement of a shoulder Ll! provided on the key shank 43.

Thus when a key is fully inserted within the heater, the switch arm is moved to a position enabling the same to contact directly with the wire or wires 33, as shown by dotted lines in Fig. 6, whereby to complete the electrical circuit used in energizing the resistors 38. It will be noted that manual pressure must be maintained on the key when the latter is inserted into the heater to keep the heating circuit closed. If manual pressure is released, the resiliency of the switch arm 45 is such that said arm will spring to a position free from engagement with the wire or wires 38, moving the key with it. It is only when a key is manually pressed fully inserted in the casing that current will flow from the vehicle battery through the heating resistors.

In view of the foregoing, it will be appreciate that the present invention provides a simple, positive and readily operated appliance which may be easily mounted on a motor vehicle so as to present a key-receiving slot acces i e r m the exterior of the vehicle. By inserting the door lock operating key of the vehicle into the slot, and holding the same in its full inserted position, current will travel through the heating resistors of the device and heat a small confined area around the key shank to an extent substantially elevating the temperature of the key shank. Usually, due to the conditions existing at the time of use of the appliance, the key is held in the gloved hand of the operator so that the heating thereof does not afford discomfort to the operator. When heated to required extent, the key is removed from the heater casing and inserted in the conventional door lock. Within a comparatively short interval of time following such insertion, the heated key will transmit its temperature sufficiently to the door lock mechanism to thaw the latter, enabling its movable parts to operate under the normal urgings of the key.

While I have illustrated and described my invention as being particularly useful as a key heating adjunct for motor vehicles, nevertheless, it will be understood that such use is merely one of others to which the present invention may be applied. In the heating of keys employed in the releasing of door locks for residential and other buildings, current may be obtained from standard house circuits, rather than the storage battery of the type used in motor vehicle starting and lighting systems. Again, the heater may be portable and operated by small dry batteries, such as those used in flashlight constructions.

I claim:

1. An electrical key heater comprising a body of dielectric material formed with a relatively narrow guide slot for the passage of the shank portion of a lock key and a recessed portion adjacent to the guide slot into which the shank portion of a key inserted through said slot may enter; an electrical heating element comprising a length of electrical resistance wire mounted on said body on either side of the recessed portion thereof and operable upon energization to heat the shank portion of a key extending within the recessed portion of said body by radiation; a first terminal carried by said body and electrically connected with said resistance wire; an outer casing surrounding said body and said heating element and provided with a face plate having an opening in registration with the guide slot of said body and a laterally enlarged attachment flange for connecting said casing to a supporting wall; a second terminal carried on said casing; and a resiliently movable switch arm electrically connected with said second terminal and movable upon insertion of the shank portion of a key through the opening of said face plate and into the recessed portion of said body into engagement with said resistance wire to complete an energizing circuit through said resistance wire and between said first and second terminals, said switch arm being normally arranged to move to a circuit-opening position in the absence of a key within th recessed portion of said body.

2. An electrical key heater for attachment to automotive vehicles comprising an outer casing provided with a flat face plafe having a relatively narrow key-receiving slot and a flange for attachment to a supporting wall; a body of dielecmounted in said body and extending outwardly i from said casing and electrically connected with said resistance wire; a second-electrical terminal carried by said casing; and aresiliently flexible switch arm electrically connected with said second terminal: and having an end portion projecting outwardly in registration fwithf he guide slot formed m ssie body, said switch m being movable into engagement with said'r complete a circuit between said terminals upon insertion of the shank portion of a lock key through the slots in said face plate and said body, and movable to a position opening the circuit for said resistance wire in the absence of a lock key within the guide slot of said body.

ALLAN J. DRUGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 854,257 Tobler May 21, 1907 1,146,758 Hadaway, Jr. July 13, 1915 2,371,534 McGrath Mar. 13, 1945 

